>>> congressman paul ryan speaking out with our jonathan karl about mitt romney, that long campaign, that tough defeat. tonight, an abc news exclusive. >>> high anxiety. an athlete struck by fear at the biggest moment of his career. a crippling anxiety millions of americans share. how does he turn his panic attack into an incredible triumph? whoo! >> and wild things. the new way boomers are keeping their lives revved up. >>> good evening. as we come on the air the investigation is widening in the general david petraeus scandal and now it includes another general. general john allen, entrusted with nothing less than winding down the nation's war in afghanistan. you should know at any given moment there are fewer than 50 four-star generals around the globe for the united states, and they are the elite of the elite. tonight, two of the most formidable, one active duty, one retired, are in the heat of the spotlight and martha raddatz tells us what happened today. martha? >> reporter: diane, the consequences of dave petraeus' infidelity are astonishing. the nation is left without a cia di